Django单元测试-无法创建django_migrations表
Django单元测试-无法创建django_migrations表
我正在尝试编写一些单元测试并使用manage.py test运行它们，但是由于某些原因，脚本无法创建django_migrations表。
以下是完整的错误信息：
Creating test database for alias 'default'...
Traceback (most recent call last):
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\utils.py", line 83, in _execute
return self.cursor.execute(sql)
psycopg2.ProgrammingError: no schema has been selected to create in
LINE 1: CREATE TABLE "django_migrations" ("id" serial NOT NULL PRIMA...
^
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\migrations\recorder.py", line 55, in ensure_schema
editor.create_model(self.Migration)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\base\schema.py", line 298, in create_model
self.execute(sql, params or None)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\base\schema.py", line 117, in execute
cursor.execute(sql, params)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\utils.py", line 68, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
return executor(sql, params, many, context)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\utils.py", line 85, in _execute
return self.cursor.execute(sql, params)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\utils.py", line 89, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\utils.py", line 83, in _execute
return self.cursor.execute(sql)
django.db.utils.ProgrammingError: no schema has been selected to create in
LINE 1: CREATE TABLE "django_migrations" ("id" serial NOT NULL PRIMA...
^
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "manage.py", line 15, in
execute_from_command_line(sys.argv)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\__init__.py", line 371, in execute_from_command_line
utility.execute()
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\__init__.py", line 365, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\commands\test.py", line 26, in run_from_argv
super().run_from_argv(argv)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\base.py", line 288, in run_from_argv
self.execute(*args, **cmd_options)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\base.py", line 335, in execute
output = self.handle(*args, **options)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\commands\test.py", line 59, in handle
failures = test_runner.run_tests(test_labels)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\test\runner.py", line 601, in run_tests
old_config = self.setup_databases()
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\test\runner.py", line 548, in setup_databases
self.parallel, **kwargs
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\test\utils.py", line 176, in setup_databases
serialize=connection.settings_dict.get('TEST', {}).get('SERIALIZE', True),
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\backends\base\creation.py", line 68, in create_test_db
run_syncdb=True,
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\__init__.py", line 141, in call_command
return command.execute(*args, **defaults)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\base.py", line 335, in execute
output = self.handle(*args, **options)
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\core\management\commands\migrate.py", line 200, in handle
fake_initial=fake_initial,
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\migrations\executor.py", line 91, in migrate
self.recorder.ensure_schema()
File "C:\Program Files (x86)\Python36-32\lib\site-packages\django\db\migrations\recorder.py", line 57, in ensure_schema
raise MigrationSchemaMissing("Unable to create the django_migrations table (%s)" % exc)
django.db.migrations.exceptions.MigrationSchemaMissing: Unable to create the django_migrations table (no schema has been selected to create in
LINE 1: CREATE TABLE "django_migrations" ("id" serial NOT NULL PRIMA...
^
)
我尝试运行这些GRANT语句，这里有一个建议：
grant usage on schema public to ; grant create on schema public to ;
但我仍然收到同样的消息。有什么想法如何解决这个问题？也许这是一个搜索路径问题？
更新
~ python manage.py makemigrations users
Migrations for 'users':
users\migrations\0001_initial.py
- Create model MyUser
~ python manage.py migrate
Operations to perform:
Apply all migrations: auth, contenttypes, sessions, users
Running migrations:
No migrations to apply.
在执行migrate之前，我尝试了makemigrations（傻瓜！），但我仍然收到之前的相同错误。迁移是否已应用？我还应该提到，我的models.py只有一个模型/表，它不由Django“管理”。
Bueller...Bueller...Beuller...有人吗？
admin 更改状态以发布 2023年5月22日
我也遇到了同样的错误，但已经解决了。在我的情况下，我相信问题出在我将Django默认模式设置为django时，在运行$ python manage.py test时，测试函数试图将一些表迁移到数据库test模式django，但是模式django尚未被创建。所以解决方法要么是（1）允许Django测试函数在模式public中搜索，要么是（2）在没有测试数据库的情况下运行单元测试。
从这个问题的被接受的答案来看，我想我的情况与问题是不同的。但我认为两者都是由于Django无法在搜索路径中找到模式而导致的。因此我在这里发布了我的解决方案。希望它能帮助类似的情况。
(django-tally-QTYVOJb0) (python3.6) D:\github\django-tally>python manage.py test
Creating test database for alias 'default'...
Got an error creating the test database: database "test" already exists
Type 'yes' if you would like to try deleting the test database 'test', or 'no' to cancel: yes
Destroying old test database for alias 'default'...
Traceback (most recent call last):
File "C:\Users\guido\.virtualenvs\django-tally-QTYVOJb0\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
return self.cursor.execute(sql)
psycopg2.errors.InvalidSchemaName: no schema has been selected to create in
LINE 1: CREATE TABLE "django_migrations" ("id" serial NOT NULL PRIMA...
对于解决方案（1）：
settings.py中的数据库设置在此之前是这样的。
if 'RDS_HOSTNAME' in os.environ:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': os.environ['RDS_DB_NAME'],
'USER': os.environ['RDS_USERNAME'],
'PASSWORD': os.environ['RDS_PASSWORD'],
'HOST': os.environ['RDS_HOSTNAME'],
'PORT': os.environ['RDS_PORT'],
'OPTIONS': {
'options': '-c search_path=django'
},
'TEST': {
'NAME': 'test', # test database name
},
},
}
现在它看起来像这样。我将public添加到了搜索路径中。
if 'RDS_HOSTNAME' in os.environ:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': os.environ['RDS_DB_NAME'],
'USER': os.environ['RDS_USERNAME'],
'PASSWORD': os.environ['RDS_PASSWORD'],
'HOST': os.environ['RDS_HOSTNAME'],
'PORT': os.environ['RDS_PORT'],
'OPTIONS': {
'options': '-c search_path=django,public'
},
'TEST': {
'NAME': 'test', # test database name
},
},
}
对于同样的错误，我做了不同的事情，虽然不是完全不同，但我直接去了psql服务器（在我的情况下）。这发生在开发过程中。因此，我没有意识到可能会有数据损失。
选择你的数据库。然后创建模式。
CREATE SCHEMA public; GRANT ALL ON SCHEMA public TO postgres; GRANT ALL ON SCHEMA public TO public;
我从https://stackoverflow.com/a/13823560/10860596获得了答案。因为我删除了所有表格，所以我遇到了问题。